The low-grade wood dissolving pulps with alpha-cellulose content below 90% were studied to prepare cellulose acetate and problems in their preparation and their remedies were studied. To do so, the low-grade softwood sulfite dissolving pulp (alpha-cellulose content, 87.5%) and hardwood prehydrolyzed Kraft pulp (alpha-cellulose content, 89%) were acetylated in the reaction system with acetic acid/acetic anhydride/sulfuric acid as will as that with an addition of organic solvent, and insoluble residues and soluble portions were studied for their characterization. As a result, atransmittance was achieved in their solution as high as that from high-grade dissolving pulps. Additionally, obtained cellulose triacetate was good in its thermal stability. These findings imply that hemicellulose acetates do not make cellulose acetate inferior in its properties and that they canbe used together with cellulose acetate. These lines of results are satisfactory for useful utilization of wood resources, but are based on small-scale experiments. Therefore, more practical preparation of cellulose acetate with a pilot plant will be becessary to investigate.In the future, global shortage of lorest resources will be more and more serious. Therefore, apractical sludies for effective use of biomass on earth will be desired for appropriate chemical conversion of biomass resources to cellulose acetates.